Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
fossilised is an adjective meaning "set in a rigidly conventional pattern of behavior, habits, or beliefs". It carries one recorded sense.
set in a rigidly conventional pattern of behavior, habits, or beliefs
“obsolete fossilized ways”
“an ossified bureaucratic system”
Definitions, synonyms and semantic relations for fossilised come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.